Water pipe Grounding not allowed by water company

[sceepe]

Ok guys I need some advice. This is new, large, institutional project, the Electrical Contractor forwarded this to me from the water company. How does he comply with this policy and NEC 250.50.

From the City water department's customer information packet: "XXX does not allow ANY ELECTRICAL GROUNDING WIRES to be connected to the incoming water lines or any part of any Backflow Prevention Assembly."

But 250.50 says:
All grounding electrodes... that are present... shall be bonded together...

Anyone ever delt with this before?
Thanks in advance

 

[jwjrw]

Ok guys I need some advice. This is new, large, institutional project, the Electrical Contractor forwarded this to me from the water company. How does he comply with this policy and NEC 250.50.

From the City water department's customer information packet: "XXX does not allow ANY ELECTRICAL GROUNDING WIRES to be connected to the incoming water lines or any part of any Backflow Prevention Assembly."

But 250.50 says:
All grounding electrodes... that are present... shall be bonded together...

Anyone ever delt with this before?
Thanks in advance

Tell them to run plastic in.... No really Ive never heard of such a thing.

 

[RICK NAPIER]

The closoet I came to a situation like this was years ago when a local POCO would not allow a grounding electrode at an outside transformer they were hooking up to even if they didn't own the transformer. I had the electrician install the ground rod and when the utlity disconnected it the responsability was on the utility not on the electrician or me.

 

[nakulak]

ask the water dept. what they mean by incoming water lines. maybe they just don't want people messing with their property ? As to the backflow preventers - maybe they have had issues with idiots trying to connect lugs to them or something like that , instead of jumping them ? if it says what you are implying, then I would definitely consult the ahj and ask them about it.

 

[cadpoint]

First of I think I'd go to the State Health Code/Requirements and find out what they say then have a meeting of the minds to clear this up.

...This is new, large, institutional project, the Electrical Contractor forwarded this to me from the water company. How does he comply with this policy and NEC 250.50...

I think somebody higher up the chain would be excited to know this is happening, bottom line.

 

[sceepe]

Update:
Talked to the water department, and they confirned that they will not accept electrical ground connection to any part of the water piping system. They noted that if they find a grounding connection on any of their yearly backflow inspections, they will send the owner a letter demanding it be removed, if it is not, they will terminate water service to the building.

Unfortunatly, at the facility in question, the water line enters the building in a mechanical space and immediatly goes to backflow preventer which they will inspect yearly.

So, as I feared, the local water company is depanding the contractor violate the electrical code if they want water. What a mess...

Water Co. inspector cited damage to copper pipes from current induced electrolysis. Funny thing is that the NEC handbook discusses this and says the problems are minimal....

 

[sceepe]

Update:
Found this via Google. It is from Richard O. Lewis, P.E.
Lewis Engineering and Consulting, Inc and was posted on the Washington Subburban Water Commision web site:

"The practice of using the water distribution piping as part of the grounding system for homes and buildings has been common place for more than 80 years [17]. It has long been assumed that alternating current (AC) has practically no effect on corrosion of the piping system. It is well known, however, that direct electrical current (DC) discharge from a metallic object can cause rapid and extensive corrosion. Documented cases of stray current corrosion have always been associated with DC.
A survey of public utilities was conducted [17] requesting case history information on experience with electrical grounding and water pipes. While many utilities acknowledged that grounding currents were thought to contribute in some instances to corrosion, the problem is essentially an external pipe corrosion problem. There is no clear indication from case histories or the literature that electrical grounding of the AC system through the water piping contributes to corrosion on the inside surface of the pipes. The water on the inside of pipes represents a far less conductive and favorable path for current discharge as compared to the soil or other metal objects in direct contact with the outside surface of the pipe. Corrosion, if it were to occur due to electrical grounding effects, should originate on the outside of the water pipe rather than the inside."

 

[zbang]

Sounds like AHJ-plumbing/mechanical and AHJ-electrical should have a discussion with the water company. When they agree...

 

[brian john]

It is virtually impossible NOT TO BOND any metallic components of a commercial structure (unless it is made of wood).

Ask them how they plan to prevent this, no more electric water heaters, no water pumps, no water fountains?

1. So the Water Company does not know its water pipe from a hole in the ground,
2. You have to comply with the NEC
3. You need your AHJ (as noted) to get involved.

 

[LarryFine]

I can't believe that this is the first time this has popped up in your area, so I'd get in touch with your local electrical inspector and ask what they've settled on.

 

[jwjrw]

I can't believe that this is the first time this has popped up in your area, so I'd get in touch with your local electrical inspector and ask what they've settled on.

I agree you know it cant be their first rodeo!

 

[tom baker]

I researched all the papers from the American Water Works Associaton Data base ( and purchased them) that dealt with water pipe grounding and shocks. Plus I have "the" AWWA study on grounding and corrosion.
So here it is:
DC causes corrosion much more than AC.
Corrosion in copper pipes is more likely an issue with the water companys pH level. Ask them what it is. We add chemicals to our water to raise the ph 7.5 to 8.5 as low pH errodes the lead and copper (and by the way ask if they comply with the EPA lead and copper rule)

And I also learned that an open neutral can cause corrosion on water pipes, even with plastic.

Most utilites use plastic pipe so the grounding is not going to cause corrosion.

And 1 water meter reader a day gets shocked pulling a meter.

But you must bond the interior metal water piping, they have no jurisdiction over that.

 

[ceb58]

I would bond as the NEC dictates. Let the AHJ, the water dept. and the owner hash out the details.

 

[sceepe]

Update:
Check out the letter I got from the water dept inspector:
Good morning..., please refer to www.charleston water.com and click on Developers, Engineers and Contractors, Backflow Regulations, Backflow Prevention Requirements, Cross Connection Control Program Manual on Backflow Prevention. Scroll to page 5 of 53 and look at 2.1.10. It states that (CPW does not allow Any Electrical Grounding Wires to be connected to the incoming water lines or any part of any Backflow Prevention Assembly). As I stated, if I see grounding wires on the incoming water lines or to the backflow preventer they will have to be removed before I will cut the water on. Or if we re-visit a site and grounds have been installed on the incoming water lines or the Backflow Prevention Assembly after we have inspected a site we will send letters to have them removed. I also explained that putting grounds on water lines causes electrolysis and caused pitting in copper pipes which caused leaks for our customers. I hope this clears up our questions on grounds that you may have had, if you have anymore questions I will be glad to assist.

 

[jwjrw]

Update:
Check out the letter I got from the water dept inspector:
Good morning..., please refer to www.charleston water.com and click on Developers, Engineers and Contractors, Backflow Regulations, Backflow Prevention Requirements, Cross Connection Control Program Manual on Backflow Prevention. Scroll to page 5 of 53 and look at 2.1.10. It states that (CPW does not allow Any Electrical Grounding Wires to be connected to the incoming water lines or any part of any Backflow Prevention Assembly). As I stated, if I see grounding wires on the incoming water lines or to the backflow preventer they will have to be removed before I will cut the water on. Or if we re-visit a site and grounds have been installed on the incoming water lines or the Backflow Prevention Assembly after we have inspected a site we will send letters to have them removed. I also explained that putting grounds on water lines causes electrolysis and caused pitting in copper pipes which caused leaks for our customers. I hope this clears up our questions on grounds that you may have had, if you have anymore questions I will be glad to assist.

I wonder if at the water plant they have any grounds on the water pipe for their service? If not then how did the power get connected. An electrical inspector would not sign off on a service with no waterpipe ground(unless it was plastic) and the poco would not cut the power on without an inspection.

Its time to have a face to face with the AHJ and get some answers.

 

[nakulak]

interesting stuff

http://www.charlestonwater.com/downloads/cross_connect/CC_001_CCC_pgm_manual_rev11_02_07.pdf

I skimmed thru the rest of the doc - it's interesting to note that there are several references in their documents (pumping stations, etc) that call for electrician to comply with NEC. I would be interested if you would post exactly what your electrical inspector has to say about this grounding issue.

 

[Dennis Alwon]

This is nothing new although it is a first I have heard about water piping. Historically it has been gas piping that has been the problem and they would not allow the gas line to be used as a grounding electrode.

As stated earlier the water lines will be bonding somewhere along the line thru an EGC. The utilities can use a fitting that will isolate the incoming water lines from the interior lines. Gosh if they are so concerned why are they not using plastic lines????:-?

 

[jxofaltrds]

"2.1.10
CPW does not allow ANY ELECTRICAL GROUNDING WIRES to be connected to the incoming water lines or any part of any Backflow Prevention Assembly."

If this is codified then the NEC does not apply.

If other electrodes are present what is the big deal?

The building code (administrative) usually governs the electrical part (code--NEC).

 

[Smart $]

"2.1.10
CPW does not allow ANY ELECTRICAL GROUNDING WIRES to be connected to the incoming water lines or any part of any Backflow Prevention Assembly."

Hmmm.... wonder how they perceive technicalities?

Typically, grounding wires are not connected to the incoming water lines. Grounding clamps are, and the grounding wires are connected to the grounding clamps. Thus, technically, the grounding wires are not connected to the incoming water lines. :roll:

 

[jxofaltrds]

Hmmm.... wonder how they perceive technicalities?

Typically, grounding wires are not connected to the incoming water lines. Grounding clamps are, and the grounding wires are connected to the grounding clamps. Thus, technically, the grounding wires are not connected to the incoming water lines. :roll:

I'm with you.

Does any other profession (trade) have code geeks like us in the electrical industry?